Switch-board for electric circuits



(Mode1.)

P. BLAK SWITCH BOARD FOR ELEG 0 CIRCUITS.

No. 243,839.. Patented July 5, 1881.

Tins Phckoillhogmphcr, Wanm'nmou. n. C.

UNITED I STATES PATENT OFFICE.

FRANCIS BLAKE, OF WESTON, MASSACHUSETTS.

SWITCH-BOARD FOR ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent N0. 243,839, dated July 5,1881.

Application filed May 31, 1881.

To all whom it may concern:

Be it known that I, FaANoIsBLAKE, of Weston, in the State ofMassachusetts, have invented a new and useful Improvement inSwitch-Boards for Electric Circuits, of which the following is aspecification.

The invention relates to that form of switchboard which contains twoseries of metallic rods, one crossing the other, each rod of one seriesbeing in a separate line or circuit, while each rod of the other seriesmay be used to make a connection between any twoline rods or circuits.

The object of my invention is to increase the number of rods of one ofthe series within a given space, and this has been accomplished bysawing slots with a fine saw across the face of a board, as neartogether as may be, and each of such width and depth that it may besubstantially filled by an exceedinglyfine wire, and then filling saidslots with such wires.

Accordingly the invention consists in a switch-board having two seriesof rods insulated from each other, one series embedded in slots acrossthe face of the board and the other series crossing the embedded rodsand provided with contact pins, as hereinafter set forth.

In the drawings, Figure l is a plan of so much of a switch-board as issufficient to illustrate my invention, Figs. 2 and 3 being respectivelylongitudinal and cross sections of the same. Figs. 4, 5, and 6 arecorresponding views of a modified form of switch-board embodying thesaid invention.

When the switch-board is constructed according to Figs. 1, 2, and 3 bothseries of rods are fixed or stationary, and connection is made betweenany rod of one series and any rod of the other series by means of asliding pin, one of which is upon each rod of one of the series. WVhenthe construction of Figs. 3, 4, and 5 is followed one series of rods hasa sliding motion over the other series, each sliding rod carrying a pinwhich may be forced into contact with any rod in the other series.

Confining the description for the present to the first-mentioned form ofconstruction, A is the table or board proper, and r r r, &c., areinsulated connecting-rods embedded in the table, as shown. B R areline-rods, and P P contact-pins, supported eachin asmall bracket, 1),sliding on one of the rods It, acoiled spring (ModeL) tending to keepthe pin in contact with the table, or with any rod 1' embedded therein.I have shown but two line-rods, all the rest bein g of thesameconstruction, and each having a bracket, 1), and pin P.

It is evident that the pin P can be moved any required distance on therod R, and that it may be made to touch any connecting-rod r withouttouching any other, however small the distance between twoconnecting-rods. Accordingly I use fine wires for the connectingrods,laying them from seven to ten to every inch of table, each wire in aslot cut across the board by a saw of a gage corresponding to that ofthe wire.

The board proper shown at Figs. at, 5, and 6 differs from the one abovedescribed in havin g a series of slots, 8, at right angles to theconnecting-rods and extending to some distance below them. In thesefigures, as in the others, A is the board, and r r r, &c., theconnecting-rods. R R are two line-rods, and P P are contact-pins; buthere the line-rods R It, instead of being stationary, slide over theconnecting-rods, and the pins P have a motion in the sliding rods to andfrom the board and connecting-rods, the coiled springs tending to keepthem out of contact with the latter. The slots 8 permit the pins P to bepushed in between'any two rods, 7', and when so pushed in a spring, it,upon the sliding rod that carries the pin causes the pin to bind againstone of the connecting-rods in the manner set forth in an application fora patent filed by me May 9, 1881. r

In the present state of the art it is unnecessary to show or referespecially to the line and ground connections or to describe the mode ofoperation; and it is evident the rods r might be placed in the lines orcircuits and the rods R or R used as connecting-rods without departingfrom my invention.

I claim-- r A switch-board provided with two series of rods insulatedfrom each other, one series embedded in slots across the face of theboard, while each rod of the other series is provided with a contact-pinand crosses every rod of the embedded series, substantially asdescribed.

FRANCIS BLAKE. \Vitnesses:

H. S. PAYSON, E. L. BLAKE.

